溶胶－凝胶法制备SiO_2膜的研究

• 作 者: 周耀 张华民 赵修仁 陈永英
• 机 构: 大连理工大学化工学院无机化学教研室
• 出 处: 硅酸盐学报
• 发表日期: 1995年01期
• 关键词: SiO_2 孔径分布 无载体 平均孔径 凝胶膜 聚合物分子 生长模式 大孔 扩散特征 纯氮气

研究了正硅酸乙酯（ＴＥＯＳ）和硅溶胶水解聚合过程中溶胶聚合物分子的生长过程。用ＴＥＯＳ和硅溶胶作原料，用溶胶－凝胶法制备了有载体和无载体的ＳｉＯ＿２膜。由不同原料引起的聚合物分子的不同生长模式将引起无载体ＳｉＯ＿２膜孔径的较大差异。用ＴＥＯＳ制得的无载体ＳｉＯ＿２膜无１．７ｎｍ以上的孔，而用硅溶胶制得的ＳｉＯ＿２膜平均孔径为７．５ｎｍ，且孔径分布狭窄。用ＴＥＯＳ作原料可在载体α－Ａｌ＿２Ｏ＿３上制得无大孔缺陷厚约０．８μｍ的ＳｉＯ＿２膜，膜的纯氮气渗透表现出Ｋｎｕｄｓｅｎ扩散特征。制膜时涂膜－干燥循环不少于三次才可避免产生大孔缺陷。

The growth of sol polymer molecules during the hydrolytic polymerization of tetraethoxysilane (TEOS) and silica sol was studied. Using TEOS and silica sol as raw materials, the SiO 2 films with and without supports were prepared by sol-gel method. The different growth modes of polymer molecules caused by different raw materials will cause large differences in the pore sizes of unsupported SiO 2 films. The unsupported SiO 2 films prepared with TEOS had no pores with a size of above 1.7 nm, while the average pore size of SiO 2 films prepared with silica sol was 7.5 nm and the pore size distribution was narrow. Using TEOS as raw material, a SiO_2 film with a thickness of about 0.8μm was fabricated on the α-Al_2O_3 support. The pure nitrogen permeation of the film showed the Knudsen diffusion characteristics. Film-forming film - drying cycle of not less than three times to avoid macroporous defects.